Conventionally, an incandescent bulb or a fluorescent lamp is used as a light source of, e.g., a backlight of illuminated sign and liquid crystal display or a lighting equipment, etc. In recent years, since it has become possible to output high power from a light-emitting diode (LED) which is a point light source and a desired intensity of illumination usable for lighting can be obtained, the LED is frequently used as a light source instead of incandescent bulbs or fluorescent lamps.
Unlike a surface light source such as a fluorescent lamp, etc., the LED has a small light-emitting area and the direct light of the LED is too bright for human eyes when looking directly thereat. It is necessary to arrange plural LEDs so that use of direct light of LED does not cause brightness unevenness when used for illumination which requires surface light emission, such as for illuminated signs.
An example in which this type of LED is used for illumination includes, e.g., an LED package which causes LEDs to illuminate uniform surface light (see, e.g., Patent document 1). In the conventional LED package described in Patent document 1, lenses having a funnel-shaped portion on the upper surface thereof and a sawtooth-shaped portion on the outer periphery thereof are arranged right above the LED so as to face each other. The conventional LED package suppresses an increase in luminance right above the LED by emitting light emitted from the LED in a direction substantially perpendicular to a package axis.